Just changed my plugs and unplugged the negative on the car battery. Everyone says the radio presets will be erased but mine did not. The only thing i had to do is the windows. Even my gps settings came back. Do i need a new battery or did i just get lucky? Also what is the lifespan of a car battery? Mine has a sticker of 05/10.

 

maybe you didnt disconnect the battery long enough. batteries should last 3-4 years before changing. i recently changed mines (4years)

you can always just take it to autozone or something and have them test your battery for free!

 

i left it disconnected for 15 minutes.

 

So why do you think you need a new battery?